Add a way to show histogram from data prepared beforehand

common.cpp

@@ -47,16 +47,22 @@ static std::string string_mangle(const std::string& str) {
 }
 
 void show_histogram(const Caches& cc, std::string Cache::*ptr, const std::string& caption, bool html, bool sort_by_val) {
+	std::map<std::string, int> histogram;
+
+	for (auto el : cc)
+		histogram[el.*ptr]++;
+
+	show_histogram(histogram, caption, html, sort_by_val);
+}
+
+void show_histogram(const std::map<std::string, int>& data, const std::string& caption, bool html, bool sort_by_val) {
 	int HIST_MAX = 20;
 
-	std::map<std::string, int> histogram;
 	std::vector<std::pair<std::string, int>> pairs;
 
 	if (!sort_by_val) HIST_MAX = 1000;
 
-	for (auto el : cc)
-		histogram[el.*ptr]++;
-	std::copy(histogram.begin(), histogram.end(), std::back_inserter(pairs));
+	std::copy(data.begin(), data.end(), std::back_inserter(pairs));
 
 	if (sort_by_val)
 		sort(pairs.begin(), pairs.end(), [&](std::pair<std::string, int>& a, std::pair<std::string, int>& b) { return a.second > b.second; });

common.h

@@ -5,6 +5,7 @@
 void htmlencode(std::string& data);
 
 void show_histogram(const Caches& cc, std::string Cache::*ptr, const std::string& caption, bool html = 0, bool sort_by_val = 1);
+void show_histogram(const std::map<std::string, int>& data, const std::string& caption, bool html = 0, bool sort_by_val = 1);
 void show_nested_histogram(const Caches& cc, std::string Cache::*ptr, std::string Cache::*ptr2, const std::string& caption, bool html = 0, bool sort_by_val = 1);
 
 int find_streak(const std::multimap<std::time_t, const Cache*>& cc, std::tm& start);